The process of determining the position of vehicles, in particular standard motor vehicles, by means of satellite navigation has been known for a long time. The accuracy which can be achieved in the process in terms of the position on the Earth's surface is now sufficient to provide the necessary data for most desired navigation purposes.
However, to date, the detection of the height of the vehicle has proven to be problematic. In this case, vertical positional inaccuracy can, for example, result in a false warning, if it is not recognized that the vehicle is located on a bridge over a road.
It is known that navigation systems, which are based on satellite navigation, can determine the height substantially less accurately than the horizontal position, which can in particular be expressed by, longitude and latitude. For example, the Galileo system has a horizontal positioning inaccuracy of 15 meters and a vertical positioning inaccuracy of 35 meters. Such positional inaccuracies are usually too large to be able to clearly assign a vehicle to a road if, for example, roads intersect bridges or tunnels.
Incorporated by reference, and DE 196 45 394 A1, which is incorporated by reference. However, this requires the additional installation of a barometric altimeter, which results in an increased outlay and higher costs.